The Impact of Multimodal Monitoring During Major Surgery on the Morbidity, Mortality and Duration of Hospital Stay in UMC Ljubljana

All patients will be visited by a member of our team a day prior to surgery to seek an informed consent and to answer any questions. A set of laboratory results (see below) will be sought.

A test (Mini Mental test) will be performed to evaluate patients' cognitive functions. Our patients are fasted.

I. PROTOCOL GROUP

Pre-induction After the insertion of an intravenous catheter all patients will receive premedication (midazolam (Dormicum®) 1-2mg iv) and an arterial catheter will be inserted under local anaesthesia. Thoracic epidural catheter will be inserted in left lateral decubitus position (intervertebral space Th 7-8, or Th 9-10 for low intestinal surgery) and test with 3 ml of 2% lidocaine (Xylocaine®) will be performed.

LiDCO Rapid® (haemodynamics), unilateral INVOS® (brain tissue oxygenation) and unilateral BIS® (depth of anaesthesia) monitors will be applied. Should there be pre-existing carotid stenosis, INVOS® sensor will be applied on the ipsilateral side. In case of pre-existing cerebral pathology, the INVOS® sensor will be applied to the contralateral side. Baseline values of nominal stroke index (SI), cardiac index (CI), BIS value, mean arterial pressure (MAP) and regional tissue oxygen saturation (rSO2) will be recorded. Basal rSO2 will be recorded prior to preoxygenation.